Phenotypic rescue of mutant brown melanocytes by a retrovirus carrying a wild-type tyrosinase-related protein gene

Development ◽  
1990 ◽  
Vol 110 (2) ◽  
pp. 471-475 ◽  
Author(s):  
D.C. Bennett ◽  
D. Huszar ◽  
P.J. Laipis ◽  
R. Jaenisch ◽  
I.J. Jackson
Keyword(s):  
Coat Colour ◽  
Specific Protein ◽  
Related Protein ◽  
Histone H4 ◽  
Wild Type ◽  
Leukaemia Virus ◽  
Mouse Cdna ◽  
Phenotypic Rescue ◽  
Moloney Murine Leukaemia Virus ◽  
Tyrosinase Related Protein

A mouse cDNA for the developmentally controlled, melanocyte-specific protein, tyrosinase-related protein 1 (TRP-1), was previously cloned and reported to show genetic linkage with the coat-colour locus brown (b) on mouse chromosome 4. The cDNA has been inserted into a retroviral vector derived from Moloney murine leukaemia virus, under the control of the human histone H4 promoter. This vector was used to infect melanocytes of the immortal line melan-b, which are homozygous for the b mutation and which display light brown pigmentation in culture. Infected cultures containing between 0.2 and 2 copies of provirus per cell displayed an altered phenotype: 20–50% of cells now had the black to dark brown colour characteristic of cultured wild-type (Black, B/B) mouse melanocytes. Thus the TRP-1 gene complements the brown mutation. We conclude that TRP-1 is the product of the wild-type b-locus.

scholarly journals Non-deletional CD8+ T cell self-tolerance permits responsiveness but limits tissue damage

2020 ◽  
Author(s):  
Emily Nestor Truckenbrod ◽  
Kristina S Burrack ◽  
Todd P Knutson ◽  
Henrique Borges da Silva ◽  
Katharine E Block ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Related Protein ◽  
Wild Type ◽  
Clonal Deletion ◽  
Cd25 Expression ◽  
Self Tolerance ◽  
Tyrosinase Related Protein

AbstractSelf-specific CD8+ T cells often escape clonal deletion, but the properties and capabilities of such cells in a physiological setting are unclear. We characterized polyclonal CD8+ T cells specific for the melanocyte antigen tyrosinase-related protein 2 (Trp2) in mice that express or lack this enzyme due to deficiency in Dct, which encodes Trp2. The size, phenotype, and gene expression profile of the pre-immune Trp2/Kb-specific pool were similar in wild-type (WT) and Dct-deficient (Dct-/-) mice. Despite comparable initial responses to Trp2 immunization, WT Trp2/Kb-specific cells showed blunted expansion, and scRNAseq revealed WT cells less readily differentiated into a CD25+ proliferative population. Functional self-tolerance clearly emerged when assessing immunopathology: adoptively transferred WT Trp2/Kb-specific cells mediated vitiligo much less efficiently. Hence, CD8+ T cell self-specificity is poorly predicted by precursor frequency, phenotype or even initial responsiveness, while deficient activation-induced CD25 expression and other gene expression characteristics may help to identify functionally tolerant cells.

scholarly journals CD8+ T cell self-tolerance permits responsiveness but limits tissue damage

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Emily N Truckenbrod ◽  
Kristina S Burrack ◽  
Todd P Knutson ◽  
Henrique Borges da Silva ◽  
Katharine E Block ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
T Cell ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Related Protein ◽  
Wild Type ◽  
Clonal Deletion ◽  
Self Tolerance ◽  
Tyrosinase Related Protein

Self-specific CD8+ T cells can escape clonal deletion, but the properties and capabilities of such cells in a physiological setting are unclear. We characterized polyclonal CD8+ T cells specific for the melanocyte antigen tyrosinase-related protein 2 (Trp2) in mice expressing or lacking this enzyme (due to deficiency in Dct, which encodes Trp2). Phenotypic and gene expression profiles of pre-immune Trp2/Kb-specific cells were similar; the size of this population was only slightly reduced in wild-type (WT) compared to Dct-deficient (Dct-/-) mice. Despite comparable initial responses to Trp2 immunization, WT Trp2/Kb-specific cells showed blunted expansion and less readily differentiated into a CD25+ proliferative population. Functional self-tolerance clearly emerged when assessing immunopathology: adoptively transferred WT Trp2/Kb-specific cells mediated vitiligo much less efficiently. Hence, CD8+ T cell self-specificity is poorly predicted by precursor frequency, phenotype or even initial responsiveness, while deficient activation-induced CD25 expression and other gene expression characteristics may help to identify functionally tolerant cells.

scholarly journals The molecular basis of brown, an old mouse mutation, and of an induced revertant to wild type.

Genetics ◽  
1990 ◽  
Vol 126 (2) ◽  
pp. 443-449
Author(s):  
E Zdarsky ◽  
J Favor ◽  
I J Jackson
Keyword(s):  
Amino Acid ◽  
Amino Acid Identity ◽  
Amino Acid Residues ◽  
Related Protein ◽  
Wild Type ◽  
Coding Region ◽  
Brown Hair ◽  
Albino Phenotype ◽  
Membrane Bound ◽  
Tyrosinase Related Protein

Abstract The murine b locus encodes the tyrosinase related protein, TRP-1, a putative membrane-bound, copper-containing enzyme having about 40% amino acid identity with tyrosinase. The protein is essential for production of black rather than brown hair pigment. We show that skin of mutant brown mice contains the same amount of TRP-1 mRNA as wild type. On sequencing the coding region of the mutant mRNA we find four nucleotide differences from the wild-type (Black) sequence. Two of these differences result in different amino acid residues encoded by the brown allele. By sequencing the TRP-1 gene from a mouse in which a reversion from brown to Black has been induced by ethylnitrosourea we are able to show that only one of these amino acid changes, which substitutes a tyrosine for a conserved cysteine, is the cause of the brown phenotype. This mutation is adjacent to another cysteine at which, in the analogous position in tyrosinase a mutation results in the albino phenotype. The sequence of the revertant is the first report of DNA sequence of an ethylnitrosourea-induced genetic change in mouse.

Molecular cloning, sequence characteristics, and polymorphism analyses of the tyrosinase-related protein 2 / DOPAchrome tautomerase gene of black-boned sheep (Ovis aries)

Genome ◽  
2009 ◽  
Vol 52 (12) ◽  
pp. 1001-1011 ◽  
Author(s):  
Weidong Deng ◽  
Yuwen Tan ◽  
Xinyu Wang ◽  
Dongmei Xi ◽  
Yiduo He ◽  
...  
Keyword(s):  
Rflp Analysis ◽  
Coat Colour ◽  
Tyrosinase Activity ◽  
Ovis Aries ◽  
Nucleotide Polymorphisms ◽  
Related Protein ◽  
Synonymous Mutations ◽  
Dopachrome Tautomerase ◽  
Flanking Regions ◽  
Tyrosinase Related Protein

Tyrosinase-related protein 2 (TYRP2) plays a pivotal role in the biosynthesis of eumelanin. Black-boned sheep have excessive melanin and eumelanin, resulting in dark (black) muscles and organs. This study was designed to investigate the effects of variants of the TYRP2 gene on black traits and coat colour of black-boned sheep. Melanin traits were measured in three populations of sheep (Nanping black-boned, Nanping normal, and Romney Marsh) and compared in this study. From the TYRP2 cDNA, all 8 exons and their flanking regions were amplified and characterized. Fifteen single nucleotide polymorphisms (SNPs) were identified in the exons and their flanking regions. Five exonic polymorphic sites, including two synonymous (c.93T>G and c.1140C>T) and three non-synonymous mutations (c.163C>T (p.R55W), c.605G>A (p.R202H), and c.1141A>G (p.T381A)), were retrieved. PCR-RFLP analysis of c.605G>A showed that the frequencies of allele G in the Nanping black-boned, Nanping normal, and Romney Marsh sheep were 0.632, 0.603, and 0.886, respectively. Sheep with the GG genotype had significantly (P < 0.05) lower tyrosinase activity, alkali-soluble melanin content, and ratio of eumelanin : total melanin than sheep with GA and AA genotypes when measured across all investigated samples but not when samples within each population of sheep were compared. However, there was no association of TYRP2 genotype at a single SNP position with coat colour across populations. Nonetheless, the two breeds with higher overall tyrosinase activity did produce darker and more varied coat colours than the breed with lower tyrosinase activity.

scholarly journals INTRACISTRONIC MAPPING OF ELECTROPHORETIC SITES IN DROSOPHILA MELANOGASTER: FIDELITY OF INFORMATION TRANSFER BY GENE CONVERSION

Genetics ◽  
1974 ◽  
Vol 76 (2) ◽  
pp. 289-299
Author(s):  
Margaret McCarron ◽  
William Gelbart ◽  
Arthur Chovnick
Keyword(s):  
Drosophila Melanogaster ◽  
Information Transfer ◽  
Large Scale ◽  
Genetic Basis ◽  
Xanthine Dehydrogenase ◽  
Specific Protein ◽  
Wild Type ◽  
Electrophoretic Variation ◽  
The Stability ◽  
Recombination Experiments

ABSTRACT A convenient method is described for the intracistronic mapping of genetic sites responsible for electrophoretic variation of a specific protein in Drosophila melanogaster. A number of wild-type isoalleles of the rosy locus have been isolated which are associated with the production of electrophoretically distinguishable xanthine dehydrogenases. Large-scale recombination experiments were carried out involving null enzyme mutants induced on electrophoretically distinct wild-type isoalleles, the genetic basis for which is followed as a nonselective marker in the cross. Additionally, a large-scale recombination experiment was carried out involving null enzyme rosy mutants induced on the same wild-type isoallele. Examination of the electrophoretic character of crossover and convertant products recovered from the latter experiment revealed that all exhibited the same parental electrophoretic character. In addition to documenting the stability of the xanthine dehydrogenase electrophoretic character, this observation argues against a special mutagenesis hypothesis to explain conversions resulting from allele recombination studies.

scholarly journals Transcriptional perturbation of protein arginine methyltransferase-5 exhibits MTAP-selective oncosuppression

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sara Busacca ◽  
Qi Zhang ◽  
Annabel Sharkey ◽  
Alan G. Dawson ◽  
David A. Moore ◽  
...  
Keyword(s):  
Small Molecule ◽  
Selective Vulnerability ◽  
Dependent Manner ◽  
Histone H4 ◽  
Wild Type ◽  
Protein Arginine Methyltransferase ◽  
Arginine Methyltransferase ◽  
Methylthioadenosine Phosphorylase ◽  
Protein Arginine Methyltransferase 5

AbstractWe hypothesized that small molecule transcriptional perturbation could be harnessed to target a cellular dependency involving protein arginine methyltransferase 5 (PRMT5) in the context of methylthioadenosine phosphorylase (MTAP) deletion, seen frequently in malignant pleural mesothelioma (MPM). Here we show, that MTAP deletion is negatively prognostic in MPM. In vitro, the off-patent antibiotic Quinacrine efficiently suppressed PRMT5 transcription, causing chromatin remodelling with reduced global histone H4 symmetrical demethylation. Quinacrine phenocopied PRMT5 RNA interference and small molecule PRMT5 inhibition, reducing clonogenicity in an MTAP-dependent manner. This activity required a functional PRMT5 methyltransferase as MTAP negative cells were rescued by exogenous wild type PRMT5, but not a PRMT5E444Q methyltransferase-dead mutant. We identified c-jun as an essential PRMT5 transcription factor and a probable target for Quinacrine. Our results therefore suggest that small molecule-based transcriptional perturbation of PRMT5 can leverage a mutation-selective vulnerability, that is therapeutically tractable, and has relevance to 9p21 deleted cancers including MPM.

scholarly journals Effect of Phlorotannins Isolated From Eisenia bicyclis on Melanogenesis in Mouse B16 Melanoma Cells

2021 ◽  
Vol 16 (5) ◽  
pp. 1934578X2110192
Author(s):  
Yuki Ohno ◽  
Shiori Kondo ◽  
Kiho Tajima ◽  
Toshiyuki Shibata ◽  
Tomohiro Itoh
Keyword(s):  
Melanoma Cells ◽  
B16 Melanoma ◽  
Physiological Effects ◽  
Related Protein ◽  
Eisenia Bicyclis ◽  
Melanin Production ◽  
Melanocyte Stimulating Hormone ◽  
B16 Melanoma Cells ◽  
Anti Cancer ◽  
Tyrosinase Related Protein

Phlorotannins isolated from brown algae, such as Eisena bicyclis, have positive physiological effects, including anti-cancer, anti-inflammatory, and anti-Alzheimer’s disease. Although phlorotannins have been shown to inhibit tyrosinase, an enzyme essential for melanogenesis, their effect on melanogenesis remains unexplored. Thus, we isolated phlorotannins from E. bicyclis and examined their effects on α-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis in murine B16 melanoma cells. Both fucofuroeckol-A (FF-A) and phlorofucofuroeckol-A (PFF-A) suppressed α-MSH-induced melanogenesis. Neither inhibited human tyrosinase (TYR) activity, but both inhibited tyrosinase-related protein-2 activity. FF-A downregulated the expression of microphthalmia-associated transcription factor and TYR, which subsequently suppressed melanin production. These results suggest that phlorotannins could be beneficial as melanin control drugs for hyperpigmentation disorders.

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